Snowfall in Philadelphia

Today, 9 February, it finally snowed significantly here in Philadelphia. In Chicago it probably snowed shortly after I moved out in September. Today’s graphic is a forecast map from philly.com using National Weather Service (NWS) data.

Snowfall in Philadelphia
Snowfall in Philadelphia

I fail to understand the divergent palette—to be fair this is not the only instance of it throughout the meteorological world. There is a split at the six-inch mark—but why? If anything, my eye would think that the 4–6 range is the heaviest, not the yellow. Snowfall is usually more of a continuous range, and so both within the blues and yellows you get that through a softer edge as the colours become more intense. And then you hit the six-inch mark and a violent shift.

I am also curious as to why the choice to use a coloured map background. Especially if the colour, a lightish green-blue is so close to the lightish blue used by the map to forecast snowfall.

In short, I think this Philadelphia map could use some attention from some designers to make the message a bit clearer.

Credit for the piece goes to the philly.com graphics department.

Hurricane Forecast Maps

In moving back to Philadelphia from Chicago, I have forsaken polar vortices for hurricanes and nor’easters. And this current weekend, it appears increasingly likely that the weather will be impacted by Hurricane Matthew, presently tearing its way through the Caribbean. So of course I am following projections and forecasts of just where this storm will be headed.

Thankfully Mashable has an article that attempts to explain just what the National Hurricane Center (NHC) means when it publishes its cone of uncertainty charts. Because, according to the article, it turns out most people do not entirely understand just what it means.

Clearly light sprinkles are forecast within the cone
Clearly light sprinkles are forecast within the cone

Credit for the piece goes to the National Hurricane Center.

Raining Maps Monday

One of the things I like about Chicago’s WGN network is its weather blog. They often include infographic-like content to explain weather trends or stories. But as someone working in the same field of data visualisation and information design, I sometimes find myself truly confused. That happened with this piece last Friday.

Pay attention to the map in the upper-right
Pay attention to the map in the upper-right

The map in the upper-right in particular caught my attention and not in the good way. The overall piece discusses the heavy rainfall in the Chicago area on Thursday and the map looks at the percentage increase in extreme weather rainfall precipitation. All so far so good. But then I look at the map itself. I see blue and thing blue > water > rainfall. The darker/more the blue, the greater the increase. But, no—check out Hawaii. So blue means less rainfall. But also no, look at the Midwest and Southeast. So does green mean anything? Beyond being all positive growth, not that I can tell. As best I can tell, the colour means nothing in terms of rainfall data, but instead delineates the regions of the United States—noting of course they are not the standard US Census Bureau regions.

So here is my quick stab at trying to create a map that explains the percentage growth. I have included a version with and without state borders to help readers distinguish between states and regions.

My take on the map
My take on the map

And what is that at the bottom? A bar chart of course. After all, with only eight regions, is a map truly necessary especially when shown at such an aggregate level? You can make the argument that the extreme rainfall has, broadly speaking, benefitted the eastern half of the United States. But, personally speaking, I would prefer a map for a more granular set of data at the state or municipality level.

Credit for the piece goes to Jennifer Kohnke and Drew Narsutis.

How Much Warmer Was 2015

When I was over in London and Dublin, most days were cool and grey. And a little bit rainy. Not very warm. (Though warmer than Chicago.) But, that is weather—highly variable on a daily basis. Climate is longer-term trends and averages. Years, again, can be highly variable—here’s looking at you kid/El Niño. But, even in that variability, 2015 was the warmest year on record. So the New York Times put together a nice interactive piece allowing the user to explorer data for available cities in terms of temperature and precipitation.

You can see the big chart is temperature with monthly, cumulative totals of precipitation. (I use Celsius, but you can easily toggle to Fahrenheit.) Above the chart is the total departure of the yearly average. Anyway, I took screenshots of Philadelphia and Chicago. Go to the New York Times to check out your local cities.

Philadelphia, PA
Philadelphia, PA
Chicago, IL
Chicago, IL

Credit for the piece goes to K.K. Rebecca Lai and Gregor Aisch.

Your Average Daily Sunshine

(Hint, it’s not me.)

I was talking with someone the other day about how I dislike warm weather. Give me nice, cool, crisp weather any day of the week. And also how I am okay without sunshine—a cool, misty, grey day is lovely. Much of weather, of course, is determined by sunlight, energy, hitting the Earth. Well, just a few weeks ago the Washington Post published a piece looking at daily sunlight. At the end of the piece it has a nice small multiple graphic too.

Average daily sunlight
Average daily sunlight

Credit for the piece goes to the Washington Post graphics department.

Water Level on Lake Michigan

Today’s a little piece for those of you who follow me from the Chicago area. It turns out that in the last 30 months, the water level of Lake Michigan has risen three feet. Despite what some people think, Lake Michigan is not an ocean—I have overheard conversations in my neighbourhood about people who went “swimming in the ocean today” and want to show them a map that points out the Atlantic is almost a thousand miles away—and is not under the same threat as the coast via melting icecaps. The Great Lakes are instead impacted by other regional and cyclical patterns, e.g. El Niño. This article by the Chicago Tribune makes use of this small but clear line chart in its discussion of those very factors.

Water levels for Lakes Michigan and Huron
Water levels for Lakes Michigan and Huron

Credit for the piece goes to the Chicago Tribune’s graphics department.

Tornadoes

I just returned from my trip to Kansas City last night. Kansas, if you did not know it, exists within what people call Tornado Alley. That means they receive a lot of tornadoes. But what are tornadoes beyond the plot points of mid-90s action films? Basically complicated micro-weather systems. So complicated we still don’t entirely understand them. But the National Post looks at explaining what we do know.

Inside a tornado
Inside a tornado

Credit for the piece goes to Andrew Barr and Mike Faille.

Boston’s Snowy 2015

Boston has finally had it. And by it I mean the snowfall that broke the record. And by record I mean the record for the most snowfall in a year. Well, at least since they started recording it in 1872. The Washington Post has a nice chart placing the season not just in context, but also showing how quickly the snow fell. Most of the snow has fallen only from 25 January onward. And winter is not yet over.

DC is puny compared to  Boston

Credit for the piece goes to Kevin Uhrmacher.

Shovelling Out of Boston

Boston and the rest of Massachusetts are attempting to dig out of the blizzard that struck them earlier this week. The Boston Globe has provided its readers with a step by step set of directions for how to best extricate people and cars from snowed in homes.

Shovelling out
Shovelling out

Credit for the piece goes to James Abundis and Javier Zarracina.